Rugby-Specific Small-Sided Games Training Is an Effective Alternative to Stationary Cycling at Reducing Clinical Risk Factors Associated with the Development of Type 2 Diabetes: A Randomized, Controlled Trial

Abstract

IntroductionThe present study investigated whether rugby small-sided games (SSG) could be an effective alternative to continuous stationary cycling (CYC) training at reducing clinical risk factors associated with the development of type 2 diabetes mellitus (T2DM).MethodsThirty-three middle-aged (48.6±6.6y), inactive men were randomized into a CYC (n=11), SSG (n=11), or control (CON, n=11) group. Participants trained 3d.wk-1 for 8 weeks, while control participants maintained normal activity and dietary patterns. Exercise duration was matched between groups, which involved CYC or SSG (four quarters, interspersed with 2-min passive recovery). Both training programs were designed to induce similar internal loads of maximal heart rate (~80-85%HRmax) and rating of perceived exertion. Pre- and post-intervention testing included dual-energy x-ray absorptiometry scan, graded exercise test, fasting 2h oral glucose tolerance test and resting muscle biopsy. Western blotting was used to assess the content of skeletal muscle proteins associated with mitochondrial biogenesis and glucose regulation.ResultsBoth CYC and SSG increased VO2 at 80%HRmax, and reduced glycated haemoglobin, glucose area under the curve (AUC; SSG, -2.3±2.4; CYC -2.2±1.6 mmol.L1(120min)1; p<0.05), and total body fat-mass (SSG -2.6±0.9%; CYC -2.9±1.1%), compared to no change in CON (p<0.05). SSG reduced insulin AUC (-30.4±40.7 µlU.mL1(120min)1; p<0.05) and increased total body fat-free mass (1.1±1.2kg; p<0.05), with no change in CYC or CON (P>0.05). There were no differences within or between conditions for protein content of peroxisome proliferator-activated receptor gamma coactivator-1α, sirtuin-1, p53, glucose transporter-4, protein kinase AKT/PKB, myocyte enhancer factor 2A, mitochondrial transcription factor, nuclear respiratory factor (NRF)-1, NRF-2 or mitochondrial complexes I-V (p>0.05).ConclusionRugby small-sided games is an effective alternative to continuous cycling for improving metabolic risk-factors associated with the prevention of T2DM. Despite such positive adaptations in clinical risk factors, there were no changes in the content of skeletal muscle proteins associated with glucose regulation and mitochondrial biogenesis.Trial RegistrationAustralian New Zealand Clinical Trial Registry ACTRN12613000874718

Effects of a 4 week touch rugby and self-paced interval running intervention on health markers in active young men

“…However, due to the cost and expertise required with DEXA, this study used bioelectrical impedance, which provides a doubly indirect assessment. Notwithstanding these differences, our results support the notion that the movement demands associated with modified team sports are important for eliciting positive changes in estimates of FFM [2,10,11,17]. The running group experienced no meaningful change in FFM, which confirms similar observations by Krustrup et al [15] after 12 weeks of running.…”

“…Both interventions appeared effective at reducing FM after only 4 weeks (touch, − 2.8 kg; running, − 0.4 kg). This finding reaffirms similar reductions after 12 weeks of modified team sport (soccer) (− 2.7 kg) and steady-state running (− 1.8 kg) [15] and 8 weeks of modified team sport (touch rugby) (− 0.7 kg) and cycling (− 0.8 kg) [2]. Our results suggest that touch rugby was more effective for reducing FM and %BF compared to running when controlling for baseline differences, which is likely explained by the different external loads imposed by the respective interventions.…”

“…Regular physical activity (PA) has been advocated as an important prevention strategy against the development of non-communicable diseases (NCDs) [1][2][3]. To date, much of the literature has focused on continuous aerobic-based training such as walking, jogging or cycling [2,4], highintensity intermittent training [5] or sporting activities [6]. The use of modified team sport activity, which refers to well-recognised sports that have been adapted (i.e.…”

Principles of Exercise Prescription, and How They Influence Exercise-Induced Changes of Transcription Factors and Other Regulators of Mitochondrial Biogenesis

“…The second study also reported no change in NRF-1 protein content after 24 sessions of continuous cycling at ~ 80 to 85% of maximal heart rate [160]. Given the paucity of available literature, more research is needed to define the effects of relative exercise intensity and training volume on exercise-and training-induced changes in NRF-1 mRNA and protein content; studies should also investigate these changes after longer recovery times.…”

“…Three studies have investigated changes in NRF-2 protein content. Whereas no change was reported after 14 sessions of MICE at 80% Ẇmax [109], or following 24 sessions of MICE at ~ 80-85% of maximal heart rate [160], an increase in NRF-2 protein content was reported after the third and seventh session of a 7-session HIIT program at ~90% of Ẇmax [16]. Due to the limited research available, no conclusions can be made on the effects of exercise intensity and training volume on changes in NRF-2 protein content.…”